Investigation Lauda Air Flight 004

niki lauda (pictured here in 1996) traveled thailand investigate crash

the flight data recorder damaged point of being unreadable, cockpit voice recorder of use. pradit hoprasatsuk, head of air safety division of thailand department of aviation, stated, attempt determine why reverser came on hampered loss of flight data recorder, destroyed in crash . upon hearing of crash, niki lauda traveled thailand. examined wreckage , estimated largest fragment 5 metres (16 ft) 2 metres (6.6 ft), half size of largest piece in lockerbie crash. in thailand, lauda attended funeral 23 unidentified passengers, , traveled seattle meet boeing representatives.

the official investigation took 8 months. did not determine cause of thrust reverser deployment. different possibilities investigated, including short circuit in system. due in part destruction of of wiring, no definitive reason activation of thrust reverser found.

as evidence started point towards thrust reversers cause of accident, simulator flights made @ gatwick airport appeared show deployment of thrust reverser survivable incident. lauda said thrust reverser not sole cause of crash. accident report states flightcrew training simulators yielded erroneous results , stated recovery loss of lift reverser deployment uncontrollable unexpecting flight crew . incident led boeing modify thrust reverser system prevent similar occurrences adding sync-locks, prevent thrust reversers deploying when main landing gear truck tilt angle not @ ground position.

the aviation writer macarthur job has said had boeing 767 been of earlier version of type, fitted engines controlled mechanically rather electronically, accident not have happened .

niki lauda s visit boeing

lauda said, annoyed me boeing s reaction once cause clear. boeing did not want anything. lauda asked boeing fly scenario in simulator. boeing refused, lauda insisted. lauda attempted flight in simulator 15 times, , in every instance unable recover. asked boeing issue statement, legal department said not issued because take 3 months adjust wording. lauda asked press conference following day, , told boeing if possible recover, willing fly on 767 2 pilots , have thrust reverser deploy in air. boeing told lauda not possible, asked boeing issue statement saying not survivable, , boeing issued statement. lauda said, first time in 8 months had been made clear manufacturer @ fault , not operator of aeroplane.

previous testing of thrust reversers

when federal aviation administration (faa) of united states asked boeing tests activating thrust reverser in flight, faa had allowed boeing establish tests of thrust reverser. boeing had insisted deployment not possible in flight. in 1982 boeing established test aircraft slowed 250 knots, , test pilots used thrust reverser. control of aircraft had not been jeopardized. faa accepted results of test.

the lauda aircraft traveling @ high speed when thrust reversers deployed, causing pilots lose control of aircraft. james r. chiles, author of inviting disaster, said, point here not thorough test have told pilots thomas j. welch , josef thumer [sic] do. thrust reverser deploying in flight might not have been survivable, anyway. thorough test have informed faa , boeing thrust reversers deploying in midair such dangerous occurrence boeing needed install positive lock prevent such event. result of findings during investigation process of lauda flight 004, additional safety features such mechanical positive locks mandated prevent thrust reverser deployment in flight.